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Fencer Vulns
medium 5.5

CVE-2022-48870 json

tty: fix possible null-ptr-defer in spk_ttyio_release

published 2024-08-21 2 y ago modified 2026-06-17 4 mo ago also EUVD-2022-53749

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

tty: fix possible null-ptr-defer in spk_ttyio_release

Run the following tests on the qemu platform:

syzkaller:~# modprobe speakup_audptr input: Speakup as /devices/virtual/input/input4 initialized device: /dev/synth, node (MAJOR 10, MINOR 125) speakup 3.1.6: initialized synth name on entry is: (null) synth probe

spk_ttyio_initialise_ldisc failed because tty_kopen_exclusive returned failed (errno -16), then remove the module, we will get a null-ptr-defer problem, as follow:

syzkaller:~# modprobe -r speakup_audptr releasing synth audptr BUG: kernel NULL pointer dereference, address: 0000000000000080 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 2 PID: 204 Comm: modprobe Not tainted 6.1.0-rc6-dirty #1 RIP: 0010:mutex_lock+0x14/0x30 Call Trace: <TASK> spk_ttyio_release+0x19/0x70 [speakup] synth_release.part.6+0xac/0xc0 [speakup] synth_remove+0x56/0x60 [speakup] __x64_sys_delete_module+0x156/0x250 ? fpregs_assert_state_consistent+0x1d/0x50 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> Modules linked in: speakup_audptr(-) speakup Dumping ftrace buffer:

in_synth->dev was not initialized during modprobe, so we add check for in_synth->dev to fix this bug.

Patch / fix

  • Linux Linux 5.15.90, 6.1.8, 6.2
  • linux Debian 14, Debian 13, Debian 12 6.1.8-1

debian advisories DEBIAN-CVE-2022-48870

  • linux Ubuntu 22.04 LTS 5.15.0-70.77
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1034.38
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1032.40
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1031.36
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1028.31
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1031.36
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1036.43
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1018.23

ubuntu advisories UBUNTU-CVE-2022-48870

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.80.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.2
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.80.1
  • kernel-source SLE Module for Development Tools 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.2
  • kernel-default SLE Workstation Extension 15 SP5, SLE Module for Legacy 15 SP5, SLE Module for Basesystem 15 SP5 +5 more 5.14.21-150500.55.80.2
  • kernel-kvmsmall openSUSE Leap 15.5 5.14.21-150500.55.80.2
  • kernel-zfcpdump SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.2

suse advisories SUSE-SU-2024:3483-1SUSE-SU-2024:3408-1SUSE-SU-2024:3227-1SUSE-SU-2024:3209-1SUSE-SU-2024:3190-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-48870 updated cvss 5.5

kernel: tty: fix possible null-ptr-defer in spk_ttyio_release

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.